Spero TherapeuticsSPRO
13F holders, Q4 2025 (December 31)At the end of Q4 2025, 56 institutions reported holding Spero Therapeutics Inc. (SPRO) in their 13F filings, up 9 from Q3 2025. 15 opened new positions and 6 sold out. The largest holders were GSK plc ($21.4M), Pfizer Inc ($5.5M) and Vanguard Group Inc. ($4.9M). 4 famous investors held it, including Jim Simons / Peter Brown (0.0% of Renaissance Technologies's portfolio), Ken Griffin (0.0% of Citadel Advisors's portfolio) and Steve Cohen (0.0% of Point72 Asset Management's portfolio).
- Company
- Spero Therapeutics Inc.
- CUSIP
- 84833T103
- Latest filing quarter
- Q2 2026
History
Number of 13F holders
Total Exit/New Position Q3 2025 → Q4 2025
| Institutions | Total Value | |
|---|---|---|
| New Positions | 15 | $3.3M |
| Exits | 6 | $448K |
All 13F filers, Q3 2025 → Q4 2025: 2,220,235 shares bought and 1,562,099 shares sold, net +658,136 shares. Counts holders who added, trimmed, opened or closed a position; split-adjusted.
Ownership 56 holders
| GSK plc | 2.68% | — | 9,190,606 | $21.4M |
| Pfizer Inc | 2.33% | No change | 2,362,348 | $5.5M |
| Vanguard Group Inc. | 0.00% | Add +4.7% | 2,083,462 | $4.9M |
| Renaissance Technologies | 0.00% | Reduce -11.9% | 1,279,522 | $3.0M |
| Alphabet Inc. | 0.08% | No change | 889,979 | $2.1M |
| Anson Funds Management LP | 0.21% | Reduce -61.0% | 625,062 | $1.5M |
| Geode Capital Management, LLC | 0.00% | Add +0.3% | 529,195 | $1.2M |
| BlackRock, Inc. | 0.00% | Reduce -0.3% | 433,616 | $1.0M |
| Citadel Advisors | 0.00% | New | 397,864 | $927K |
| Two Sigma Investments, LP | 0.00% | Add +654.2% | 372,570 | $868K |
| Susquehanna International Group, LLP | 0.00% | New | 293,700 | $684K |
| Informed Momentum Co LLC | 0.06% | Reduce -22.8% | 218,084 | $508K |
| Two Sigma Advisers, LP | 0.00% | New | 216,600 | $505K |
| State Street Corp. | 0.00% | Add +10.1% | 210,151 | $490K |
| Ionic Capital Management LLC | 0.53% | Reduce -6.1% | 195,939 | $457K |
| Gsa Capital Partners LLP | 0.04% | Add +67.4% | 178,930 | $417K |
| Intrepid Family Office LLC | 0.37% | Add +50.0% | 165,000 | $384K |
| Jane Street Group, LLC | 0.00% | Add +268.3% | 158,344 | $369K |
| Sei Investments Co. | 0.00% | New | 132,010 | $308K |
| OMERS ADMINISTRATION Corp | 0.00% | New | 131,127 | $306K |
| Northern Trust Corp. | 0.00% | Reduce -6.7% | 120,984 | $282K |
| Squarepoint Ops LLC | 0.00% | New | 119,434 | $278K |
| UBS Group AG | 0.00% | Add +329.7% | 116,447 | $271K |
| Bridgeway Capital Management, LLC | 0.01% | No change | 114,800 | $267K |
| ADAR1 Capital Management, LLC | 0.02% | Reduce -1.5% | 113,839 | $265K |
| Shay Capital LLC | 0.02% | Reduce -5.3% | 60,289 | $140K |
| Point72 Asset Management | 0.00% | New | 43,579 | $102K |
| Quadrature Capital Ltd | 0.00% | New | 37,799 | $88K |
| Simplex Trading, LLC | 0.00% | Add +368.4% | 35,686 | $83K |
| Capital Asset Advisory Services LLC | 0.00% | No change | 32,548 | $82K |
| Axxcess Wealth Management, LLC | 0.00% | No change | 32,548 | $76K |
| Three Seasons Wealth, LLC | 0.01% | No change | 30,000 | $70K |
| Dimensional Fund Advisors LP | 0.00% | Add +2.7% | 29,768 | $69K |
| Charles Schwab Investment Management Inc. | 0.00% | No change | 28,565 | $67K |
| Invesco Ltd. | 0.00% | Add +11.8% | 24,705 | $58K |
| Millennium Management | 0.00% | New | 24,107 | $56K |
| Assenagon Asset Management S.A. | 0.00% | Reduce -49.6% | 18,636 | $43K |
| Torrey Growth & Income Advisors | 0.01% | Add +7.9% | 17,025 | $40K |
| XTX Topco Ltd | 0.00% | Reduce -55.1% | 15,175 | $35K |
| Texas Yale Capital Corp. | 0.00% | No change | 10,000 | $23K |
| Tower Research Capital LLC (TRC) | 0.00% | New | 7,215 | $17K |
| Jones Financial Companies LLLP | 0.00% | New | 6,477 | $15K |
| JPMorgan Chase & Co. | 0.00% | Add +2176.7% | 5,373 | $13K |
| FNY Investment Advisers, LLC | 0.00% | No change | 5,300 | $12K |
| Cullen/Frost Bankers, Inc. | 0.00% | New | 3,000 | $7K |
| Bank of America Corp. | 0.00% | Add +1.5% | 744 | $2K |
| Morgan Stanley | 0.00% | Reduce -99.3% | 313 | $729 |
| Osaic Holdings, Inc. | 0.00% | No change | 290 | $675 |
| Wells Fargo & Company | 0.00% | No change | 200 | $466 |
| Rockefeller Capital Management L.P. | 0.00% | No change | 200 | $466 |
| US Bancorp \de | 0.00% | No change | 151 | $352 |
| BNP Paribas Financial Markets | 0.00% | No change | 40 | $93 |
| Citigroup Inc. | 0.00% | New | 17 | $40 |
| SageView Advisory Group, LLC | 0.00% | New | 17 | $40 |
| Farther Finance Advisors, LLC | 0.00% | New | 10 | $23 |
| SBI Securities Co., Ltd. | 0.00% | Reduce -10.0% | 9 | $21 |
"% of holder's portfolio" is SPRO's weight in each manager's 13F, not the share of Spero Therapeutics Inc. the manager owns.